[graemep]

True, but that is at a different level and a bit more complex. I was talking about the problem of government finances - i.e. government revenue vs expenditure.

Setting aside money, and where you put it, makes a big difference. It might be in a sovereign wealth fund, or used to finance govt debt (as in the small fund that exists in the UK) or invested in shares by a private pension fund, or be a liability of a past employer. In some of those cases value might be generated in another country.

You are right in principle but there are big practical differences too.